In this Grade 6 lesson from enVision Mathematics Chapter 4, students learn how to write and solve addition and subtraction equations using inverse relationships and the properties of equality. Students practice isolating a variable by applying inverse operations, such as subtracting to undo addition or adding to undo subtraction, and use bar diagrams and pan balances as visual tools. Real-world word problems guide students in setting up and solving one-variable equations like n + 7 = 25 and y - 19 = 34.
Section 1
Subtraction and Addition Properties of Equality
Subtraction Property of Equality
For all real numbers , , and , if , then .
Addition Property of Equality
For all real numbers , , and , if , then .
When you add or subtract the same quantity from both sides of an equation, you still have equality.
Section 2
Writing One-Step Addition and Subtraction Equations from Word Problems
Use variables to represent unknown quantities in word problems and construct simple equations that can be solved using addition or subtraction. This involves identifying the unknown, assigning it a variable, and translating the problem into an equation of the form or .
Expand to review the lesson summary and core properties.
Section 1
Subtraction and Addition Properties of Equality
Subtraction Property of Equality
For all real numbers , , and , if , then .
Addition Property of Equality
For all real numbers , , and , if , then .
When you add or subtract the same quantity from both sides of an equation, you still have equality.
Section 2
Writing One-Step Addition and Subtraction Equations from Word Problems
Use variables to represent unknown quantities in word problems and construct simple equations that can be solved using addition or subtraction. This involves identifying the unknown, assigning it a variable, and translating the problem into an equation of the form or .